The present invention relates to a tripod plate, a tripod, a portable camera, a connection element for connecting a portable camera to a tripod plate and an interface system for mechanically fastening a camera. Portable cameras can be fixedly connected to a tripod or a pan head of a camera via such a mechanical interface, the so-called tripod plate.
Tripod plates serve, in particular, to mechanically fix portable cameras within a short period of time. A rapid mechanical fixation of a camera is needed for the flexible use of portable cameras.
As a rule, the demands made on portable cameras are contradictory. On the one hand, they should have a weight that is as small as possible to be suited for mobile use. This, however, additionally requires a separate recording device and a separate power supply for the cameras. Portable video cameras for professional uses, the so-called broadcast cameras, normally have a weight ranging from 5 to 12 kilograms.
In contrast to the portable cameras used in the consumer field, very high demands are made on the image quality, in particular the resolution of the recorded video signal, in broadcast cameras. As for the quality of the video signals to be recorded, a rough distinction can be made between the following levels: VHS quality, distribution quality and contribution quality. In the consumer field the attempt is made to achievexe2x80x94with a minimum number of meansxe2x80x94a video signal quality that, if possible, should be better than that of VHS video recorders.
In the professional field a distinction is made between distribution and contribution quality. While video signals used for xe2x80x9cdistributionxe2x80x9d, i.e. for broadcasting to TV viewers, have a much better picture quality than the VHS quality, video signals suited for xe2x80x9ccontributionxe2x80x9d have to meet even higher demands. An important use for portable professional video cameras is ENG (electronic news gathering). In ENG shots are taken by camera teams on the spot, for instance for newscasts. These are later compiled or edited for a newscast and then broadcast. A further application for portable video cameras with high quality demands is EFP (electronic field production). In both cases, high demands are made on the quality of the video signals, in particular the resolution, because the video signals have often to pass through several image processing stages after shooting. Normally, in post-production stages image sequences are newly edited, cross-faded, cut, subtitled, etc. As a rule, each of these stages will deteriorate the quality of the image signal. To guarantee a specific minimum quality level for the image signals which are broadcast to the TV viewer in the end, i.e. the distribution quality, special demands must be made on the shots.
The enhanced image quality produces a considerably larger video signal flow than is standard with image signals in the consumer field. As a rule, the recording methods used in consumer devices for the video signal are not suited for the professional field. Special recording formats have become accepted as magnetic recording methods for the broadcasting field. These derive from four basic forms: 1. analog composite, 2. analog components, 3. digital composite, 4. digital components. Digital recording formats are increasingly used. The digital composite signal is a digitalization of the analog composite color video signal. To this end the video signal is normally scanned and quantized with a multiple of the color subcarrier frequency. Such digital magnetic recording formats include, e.g., the D2 format (of Ampex and Sony) and the D3 format (of Panasonic). An improved image quality can be achieved with the digital component technique. The analog component signals (RGB) are here encoded digitally. Such magnetic recording standards include, e.g., the Digital Betacam format (of Sony) or the magnetic recording format D6 (of Panasonic).
The recording of video signals on magnetic disks, in particular hard disks, as are used in every PC, gains more and more importance because of its increased storage capacity. This recording medium has the advantage that it can be used much more easily together with electronic post-production devices, for instance computer-aided cutting devices (non-linear editing).
The great variety of recording formats often requires a conversion into one or several of the other recording formats, depending on the respective use.
The recording capacity of the recording device within the portable camera is limited, in particular because of the small dimensions of the camera. During mobile use, coupling to an external recording device is virtually impossible. During stationary use, however, an external recording device is often used. That is why portable video cameras have external connections to provide the video signal for external recording.
During the mobile use of such a camera, the camera requires not only a recording device of its own, but also its own power supply. However, since the capacity of accumulators is limited, an external power supply is also connected to the camera during stationary operation, if possible. A portable camera comprises additional electrical connections for this purpose.
As a rule, there are provided not only electrical connections for an external power supply and an external recording device, but also for a number of additional signals. These signals include, for instance, a separate viewfinder signal, an audio signal or a control signal for camera operation. Such control signals are inter alia a control signal for focus, aperture and a camera on/off signal. With the help of such signals, it is e.g. possible to realize a remote control of the camera so that shots are also possible without an operator being on the spot.
To be suited for both mobile and stationary use, broadcast cameras are provided on their bottom side with a shoulder support formed by an indentation in the central portion on the bottom side of the camera housing. FIG. 1 shows such a broadcast camera 2 which in the lower portion comprises a shoulder support 4. At the front and rear end of the bottom side of the camera housing, i.e. in front of and behind the indentation formed for receiving a shoulder, there are provided the sections which are mountable on a tripod plate and fixedly connectable to said plate. A broadcast camera is thereby suited for both mobile and stationary use.
To enable the camera to change very rapidly between a mobile use and a stationary use in the case of on-the-spot shooting, quick-action clamping plates are nowadays used as a rule for mechanically fixing the camera onto the plates very rapidly, but also for disconnecting the same again.
The tripod plate serves here as a mechanical interface between the camera and a pan head of the camera. Normally, such pan heads are positioned on a tripod, but can just as well be secured to a camera crane or another mechanical support device. The rotatable pan heads permit camera pans and tilts in a controlled manner.
With conventional (quick-action clamping) tripod plates, a portable camera can rapidly be mounted on and fixed to a pan head and also be detached therefrom again. Whenever the camera is mounted, it must be connected to all external lines in addition to its mechanical fixation to the tripod plate. Accordingly, when the camera is removed, it is not only the mechanical mounting that has to be detached, but all of the connected lines have to be disconnected again for a mobile use of the camera.
For securing a camera a conventional tripod plate is provided in its front portion with a dovetail guide into which an insertion member formed complementary thereto is introduced during mounting of the camera on the tripod plate. The camera is subsequently fixed onto the tripod plate with the help of a locking means. Such a tripod plate is e.g. known from DE-U1 256 13 027. In view of the size of the camera and its weight, a person can only introduce the insertion member at the bottom side of a portable camera under great difficulties. The reason is that the insertion member must be accurately xe2x80x9cthreadedxe2x80x9d into the dovetail guide and does not allow for an inaccurate positioning of the camera on the tripod plate.
While being mounted and locked, a camera is first seated on the tripod plate in a mechanically fixed manner. However, even a minimum wear of the fastening device on the tripod plate or camera may lead to a play and thus to a rocking movement of the camera on the tripod plate.
Said drawback is overcome by tripod plates which allow a separate clamping action. The fixed camera is additionally preloaded by a manually operated lever mechanism on the tripod plate, so that the camera itself will no longer shake or rock in the fastening device when there is a minimal play. Such a two-stage fastening to a tripod plate has however the effect that a portable camera cannot be used in a very flexible way. A change from a mobile to a stationary use is accompanied by a multistage locking and clamping procedure.
It is the object of the present invention to provide a tripod plate, a tripod, a portable camera and a connection element for an easier and faster mounting of the camera on a tripod plate.
The invention is based on the idea to simplify the mounting of a camera on a tripod plate. To this end, a camera is first mounted with only one end on the tripod plate. The camera is held at said end of the tripod plate in such a manner that it can perform substantially only a rotational movement around the holding point for mounting the other end on the tripod plate. Upon mounting of the opposite end the camera is finally fixed by means of an automatic locking means.
According to an advantageous embodiment of the invention the camera is fixed and clamped at the same time. A mechanical preload is created by a preloading means upon mounting of the camera so that the camera is fixedly clamped onto the tripod plate by the mechanical preload between the tripod plate and the camera. The production of such a load no longer requires the manual operation of a lever. While the camera is being mounted, a preload is automatically produced via the lever xe2x80x9ccameraxe2x80x9d by the rotational movement defined for the camera during insertion into a holding element of the tripod plate. Instead of two successive stages, only one is now required. The reason is that the preload is produced in that the camera can only be mounted against the pressure of the preloading means. According to the invention a camera is thereby automatically locked and clamped on a tripod plate in an easy way. Thus a person can mount the camera rapidly and reliably on the tripod plate of the invention without any awkward handling.
Moreover, the camera need no longer be mounted as a whole and in a positionally accurate manner on the tripod plate. First of all, only a projection of the camera is hooked in at the front end of the tripod plate. Even under adverse conditions such an insertion can be accomplished much more easily than a positionally accurate mounting of the whole camera on the tripod plate.
The tripod plate is equipped with a preferably cylindrically shaped bolt as the holding element. The bolt represents the rotational axis for the camera. A rotational movement of the camera is thereby supported by the shape of the bolt.
The camera can be mounted in a particularly easy way if it comprises two lateral projections that are cooperating with correspondingly arranged bolts as the axis of rotation. To this end the bolts are laterally arranged in respective recesses on the tripod plate. The camera is thereby retained at said end without any cumbersome mechanical xe2x80x9cthreadingxe2x80x9d operation.
At the other end the tripod plate comprises a locking means which includes a slide, a locking element, a spring and a safety means. The locking element is fixedly connected to the slide so that the locking element can be moved via the slide for unlocking purposes. The slide and the locking element that are movably arranged on the tripod plate are under a preload which is moving both members into the xe2x80x9clockingxe2x80x9d state. The locking mechanism is held by a release mechanism in the xe2x80x9cnon-lockedxe2x80x9d state until release. In the xe2x80x9clockedxe2x80x9d state the slide releases a safety means which automatically prevents an unlocking of the camera. No additional operation is thus required for locking the camera on the tripod plate.
The release mechanism for the locking means is activated by pins that are provided on the upper side of the tripod plate in the area of the locking means. In the xe2x80x9cnonlockedxe2x80x9d state the movably arranged pins project from the tripod plate because of their preload. When a camera is mounted, the pins are pressed down, thereby releasing the locking mechanism which fixes the camera in said area. A fully automatic locking of the camera is thereby made possible.
A means which preloads the camera such that the camera cannot move within the fastening device, even despite a slight play, is provided for clamping the camera. To this end a plate which is acted upon by a spring from below is provided in the area of the bolt. Said plate is arranged at the side of the point of rotation on the tripod plate. After the nose has been hooked into the holding element, the camera is also mounted on the other rear end of the tripod plate via a rotational movement. Said rotational movement is only possible against the resistance of the preloaded plate. The nose of the camera or of the connection element which can be fastened to the camera is shaped such that the camera can only be inserted under a preload while being mounted. The preload can be produced in an easy manner with the help of a metal plate and spring elements arranged thereunder. The preload is preferably so high that the camera can just overcome the preload by its own weight during the rotational movement for the mounting of the rear end. As a result, the camera can very easily be mounted and locked on the other end. To this end the preload is normally about two to three times the weight of the camera.
A connection element is provided according to a further aspect of the invention. Said connection element can be fastened at its upper side by a fastening device to the bottom side of conventional portable cameras. At least one downwardly protruding nose is provided on the bottom side of the connection element. Said nose can be hooked into the bolt of the tripod plate. Preferably, a projection of the nose projects towards the front side of the camera. The camera is then first hooked with its front lower end into the holding element of the tripod plate. Subsequently, the camera is just lowered at its rear end onto the tripod plate.
The connection element may be designed such that it comprises two noses respectively arranged at the side. To this end the connection element consists essentially of three components, namely a cover plate with the fastening device for a camera on the upper side, and two side elements. At their front lower end said side elements comprise projections and additionally effect a xe2x80x9crollingxe2x80x9d of the camera upon mounting on the tripod plate, whereby the preload is built up. After the hooking action the camera is bound to rotate for mounting the other end of the camera due to two lateral elements on the connection element with the projections on the front lower end thereof. The camera can thereby be xe2x80x9cthreadedxe2x80x9d and mounted on the tripod plate in an easy manner.
A further aspect of the invention relates to an interface system which consists of a tripod plate according to the invention and a connection element of the invention. The cooperation of the two components permits a fast mounting and clamping of the camera, the tripod plate being useable with the help of the connection element also for those cameras that originally have not been intended for the tripod plate according to the invention.
According to a further aspect of the present invention a fast change between a mobile and a stationary use of a portable camera is rendered possible in that an electrical interface is provided in addition to the mechanical interface permitting a fast mechanical change. An electrical interface which is coupled with the mechanical interface makes it possible that an electrical connection is established at the same time as the mechanical connection and can also be disconnected again.
To this end all of the camera connections, or at least the most important ones, such as the power supply and the video signal, are guided across electrical contacts preferably provided on the bottom side of the camera and on the upper side of the tripod plate. While the camera is being mounted on the tripod plate, the respective contact elements are automatically contacted, thereby permitting a transmission of electrical signals between the camera and the tripod plate. To this end the electrical contacts on the bottom side of the camera are internally or externally connected to the corresponding camera connections, and the contact elements on the upper side of the tripod plate to the corresponding electrical connection lines of the external devices. The connectors/sockets of the respective connections can directly be arranged on the surface of the sides of the tripod plate or inside the tripod plate. Finally, in the case of an arrangement inside the tripod plate, the connectors/jackets are advantageously flush with the side surface of the tripod plate. The connections can also be led out of the tripod plate at the side via cables.
An electrical contact can thus be established at the same time as the mechanical connection, so that a change from the mobile use to a stationary use on a pan head or on a tripod can now be carried out much faster than in former times.
For this purpose tripod plates are equipped on their upper side with corresponding contact elements. At the same time, the cameras are provided with correspondingly arranged contact elements on their bottom side.
Preferably, the contact elements of the camera are provided on the bottom side of the connection element so that they can be brought into contact with the corresponding contact elements of the tripod plate upon mounting. To permit an electrical connection with the corresponding camera connections, electrical connections that can each be connected to the corresponding camera connections are therefore provided on the outsides of the connection element. The electrical connections of the connection element are designed either as sockets/connectors that are directly arranged on the side surface of the connection element, or they are led out of the side surface of the connection element via cables. Advantageously, depending on the cable assignment, the cables have the corresponding connector (socket) and the necessary length to be directly connectable to the corresponding connection on the camera or the lens.
This provides for an interface device in the case of which, on the one hand, the camera is equipped with a connection element that comprises contact elements on its bottom side and, on the other hand, a tripod plate is provided with correspondingly arranged contact elements on the upper side. Thanks to said combination such an interface device improves the formerly known interface devices that have only been of a mechanical type.
Portable broadcast cameras are provided on their bottom side with a recess for placing the camera in an improved manner on an operator""s shoulder. Thus, when the camera is mounted on a tripod plate, it is only the front and rear section of the bottom side of a camera that is in contact with the tripod plate. Electrical contact elements may be provided in the area of the front and rear sections. Advantageously, the contacts are provided in the front section. It is thereby possible to provide mechanical elements in the rear portion for locking the camera.
In general, a pan head of a camera is provided with a swing arm for moving the camera. The handle of said swing arm is equipped with an setting means for controlling the zoom setting of the camera. Apart from the power supply and the video signal produced by the camera, the zoom control signal thus belongs to the essential electrical signals for which electrical contact elements are provided on the bottom side of the camera or the bottom side of the connection element and on the upper side of the tripod plate. With minimum efforts for the interface, as much time as possible can be saved because it is only in exceptional cases that further lines are connected to the camera during stationary use.
Advantageously, further setting signals, such as focus setting and aperture setting of the camera, and an audio signal produced by the camera are transmitted via additional electrical contact elements.
Broadcast cameras are all the more suited for a mobile use the smaller their weight and their dimensions are. It is therefore desired to limit the number of the components provided in the camera just to the really necessary ones. However, when specific components are to be positioned somewhere else, these must be provided for as external accessory devices. This makes the camera not only more inconvenient during stationary operation, but also requires much more time for cabling. The number of accessory devices should therefore be limited to a minimum.
According to a further aspect of the present invention accessory means are therefore arranged inside the tripod plate. This has the special advantage that said additional components are electrically connected to the tripod plate at the same time. A separate cable laying is no longer required. The possibilities of using a portable camera can thus be further improved by said measure without any extra work.
Advantageously, a distributing means is provided in the tripod plate. This distributing means makes it possible to pass a video signal to several external connections at the same time.
In particular, signal processing means may be arranged in the tripod plate according to the invention. As a result, video signals which are produced by the camera can e.g. be converted into a different video signal format. In view of the many possible signal formats, hardware components provided for different video formats (e.g. of different manufacturers) can easily be combined with one another.
According to a further aspect of the invention digital recording means can be arranged in the tripod plate. Video signals of the camera can e.g. be recorded on hard disks, as are used in commercial PCs. While such hard disks can normally not be accommodated in portable cameras because of the shocks produced, the recording capacity of a broadcast camera can considerably be increased with such an arrangement. Moreover, the electronic postproduction of the recorded video signals is rendered much more easier because a PC can directly access the signals stored on the hard disk for the postproduction of the video signals. A time-consuming recopying or rerecording to a hard disk is thus dispensed with. Moreover, electronic reporting is thereby facilitated, for image signals which are stored on a hard disk can be transmitted much faster and easier via a data network, e.g. the internet, to another place. Advantageously, the tripod plate is designed such that the digital recording medium in the tripod plate can be exchanged very easily. In particular those hard disks that are produced for notebook-like PCs are suited for digital recording. Other digital recording media of a smaller size can also be used, e.g., flashdisks which have the additional advantage that they are very sturdy from a mechanical point of view. These recording devices can also be used for control signals or parameters of/for the camera alone. In this case recording devices that are smaller and also more sturdy can be used without any problem.
According to a further aspect the tripod plate has arranged therein a receiving means which permits a remote control, in particular a wireless remote control, of the camera. A remote control is always advantageous whenever on account of external conditions, e.g. not enough space, or because of special environmental conditions, or when several cameras are operated from a central place, an operator cannot directly operate the camera. In such a situation there is normally also no space for an additional device. When such a receiving means can be accommodated within the tripod plate, the possibility of a remote control for broadcast cameras is considerably enhanced.
According to a further aspect the tripod plate contains a transmitting means for the wireless transmission of the video signal received by the camera.
Advantageously, the tripod plate is designed such that in response to the respective application it can be equipped with any desired electric device. To this end the tripod plate has provided therein a recess which can respectively receive modules of an identical size. Different modules with respectively different signal processing devices are provided for different applications; for instance, the above-mentioned electronic means which according to the invention can be arranged in the tripod plate. Such a tripod plate can then be used in a particularly flexible manner.
According to a further aspect of the invention the opposite electrical contact elements of the camera or of the connection element, and the tripod plate are designed differently. While the contact elements of the one side may e.g. be designed as flat contacts, the opposite electrical contact elements are movable substantially in a direction perpendicular to the surface, so that said contact elements are mechanically preloaded and therefore project from the surface. A simple and particularly sturdy contact with the opposite contact elements is thereby established.
Advantageously, the tripod plate or the camera contains a means which after the camera has been mounted on the tripod plate checks automatically whether a proper contact has been established with the contact elements. Thus contacting errors can be detected immediately, whereby a situation is avoided in which because of a faulty contacting an inadequate recording or no recording is carried out without this being noticed by the operator.
In particular, an optical display means which displays a positive and/or negative test result of a contact checking operation is provided on the tripod plate or on the camera. For instance, directly after mounting one can see whether the camera has been properly contacted and whether a recording operation can directly be continued from the tripod.